Short answer

Use regular expressions (RegExp) with the g parameter, global search

Fragment

/**
 * Ejemplo simple
 *
 */
var cadena = "Test abc test test abc test test test abc test test abc";
var re = /abc/g;
var resultado = cadena.replace(re, '');
console.log(resultado);

Observations

Regular expressions are not trivial since certain characters have an effect on the way the regular expression is interpreted. The processing of these must be applied only to secure strings or they should be escaped before being processed. Here is a more complete example.

/**
 * Ejemplo simple modificado
 *
 */

// Tomado de 
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
function escapeRegExp(string) {
  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); 
}

// Cadena a procesar
var cadena = "Test abc test test abc test test test abc test test abc";

// Simular entrada de usuario
var entradaUsuario = "abc";

// Aplicar la función para escapar la entrada de usuario
var re = new RegExp(escapeRegExp(entradaUsuario),'g');

// Aplicar reemplazo
var resultado = cadena.replace(re, '');

// Imprimir en la consola el resultado
console.log(resultado);

Font

Response to How to replace all occurrences of a string in JavaScript?

See also

• Safe way to escape user input to be processed by regular expressions in JavaScript

String.replace() accepts a string or a RegExp object as its first parameter .

If you want to replace all "abc", just use a regular expression with the /g( global ) modifier, which indicates that all occurrences are replaced.

resultado = str.replace(/abc/g, '');

And if you want to ignore case, use the modifier /i( ignore case ):

resultado = str.replace(/abc/gi, '');

You should only take into account escaping special characters, preceding them with \. For example, to replace "abc.", the regular expression would be /abc\./g. The special characters are:

\   ^   $   .   |   ?   *   +   (   )   [   {

And in the replacement, escape $as $$.

This is explained in Safe way to escape user input to be processed by regular expressions in JavaScript

General case:

The same can be done in the general case, to replace any substring, and escaping all special characters.

function reemplazarTodos( texto, reemplazarQue, reemplazarCon, ignorarMayMin){
  var reemplazarQue = reemplazarQue.replace(/[\\^$.|?*+()[{]/g, "\\$&"),
      reemplazarCon = reemplazarCon.replace(/\$(?=[$&`'\d])/g, "$$$$"),
      modif = "g" + (ignorarMayMin ? "i" : ""),
      regex = new RegExp(reemplazarQue, modif);
  
  return texto.replace(regex,reemplazarCon);
}


//Prueba
var texto = "--abc.--abc.---abcX---AbC.",
    resultado1 = reemplazarTodos(texto, "abc.", "def"),
    resultado2 = reemplazarTodos(texto, "abc.", "def", true);
console.log(texto, "⟶", resultado1);
console.log(texto, "⟶", resultado2);

Extending the prototypes of the original types ( built-in prototype) is not recommended, but in order to show a different solution I am going to give an example of how to do it by modifying the prototype of String.

Regular expression based implementation

String.prototype.replaceAll = function(search, replacement) {
    var target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};

Implementation based on Split and Join (Functional)

String.prototype.replaceAll = function(search, replacement) {
    var target = this;
    return target.split(search).join(replacement);
};

It would be used like this:

console.log(cadena.replaceAll("abc"));

Note: do not use this method in real code

An alternative to regular expressions can be:

str = "Test abc test test abc test...".split("abc").join("");

The general pattern is:

str.split(búsqueda).join(reemplazar)

This used to, in some cases, be faster than using protoypesand regular expressions but that doesn't seem to be the case in modern browsers. Therefore this should only be used as a quick fix to avoid regex escaping but not for actual code that is going to go into production.

See the original answer